The subject technology generally relates to flow measurement systems, and more particularly to power supplies in flow measurement systems.
When designing a battery operated device, battery life is usually considered to be mainly dependent on battery capacity and average current consumption. When designing a battery operated device to be operated for an extended period of time, another parameter to consider is battery self-discharge rate. Current consumption may vary significantly in some battery operated devices and their power supplies need to meet the varying power demand as well. FIG. 1 illustrates a block diagram of a prior art power supply system 100 for a battery operated device with varying current consumption, which uses a capacitor as a temporary storage. As shown, an input of a DC-DC converter 101 is coupled to one end of a battery 102. A capacitor 103 and a wireless communication unit 104 are coupled in parallel between an output of the DC-DC converter 101 and the other end of the battery 102. The battery 102 charges the capacitor 103 so that the capacitor 103 can supplement the current to the wireless communication unit 104 when the wireless communication starts.